A Class of General Transient Faults Propagation Analysis for Networked Control Systems

Transient faults are a dominant kind of threat to system safety in networked control systems (NCSs) due to their high occurrence rate and wide variety. However, they are hardly detected accurately in NCSs because of their unpredictable nature and short duration. Hence, fault propagation analysis (FPA) has become a bottleneck issue for fault-tolerant control in NCSs, which is used to analyze the fault effects and identify the approximate zone where transient fault occurred. In this paper, an innovative ontology-based FPA approach (ontologyFPA) is proposed to analyze transient fault propagation effects in NCSs. From the view of object-centered ontology, function, behavior, and structure models are built to reflect system abstraction hierarchies, and fault propagation effects and traces are identified from behaviors to functions through the mapping relationships of abstraction models. From the view of system-centered ontology, information-based workflows are employed to represent system independence in which fault propagation is investigated by excavating different effect traces among serial tasks in control loops. To illustrate the processes of propagation analysis, the application of ontologyFPA in a steam generator water level control system is presented. Finally, based on a unified simulation platform described by the architecture analysis and design language (AADL), two types of faults are injected to inspect the fault propagation processes between abstraction hierarchies, while another type is injected to investigate the processes in workflows. The results demonstrate that the proposed approach is effective in terms of identifying transient fault propagation effects and traces.